Infrastructure at your Service
By Franck Pachot . In a previous post I introduced Tibero as The most compatible alternative to Oracle Database. Compatibility is one thing but one day you will want to compare the performance. I’ll not do any benchmark here but show you how you we can look at the performance with TPR – the Tibero Performance Repository – as an equivalent of AWR – the Oracle Automatic Workload Repository. And, as I needed to run…
PostgreSQL, like all other database engines, modifies the table and index blocks in shared buffers. People think that the main goal of buffered reads is to act as a cache to avoid reading from disk. But that’s not the main reason as this is not mandatory. For example PostgreSQL expects that the filesystem cache is used. The primary goal of shared buffers is simply to share them because multiple sessions may want to read a…
By Franck Pachot . Note that I’ve written previously about Oracle Standard Edition 2 licensing before but a few rules change. This is written in May 2020. TL;DR: 4 vCPU count for 1 socket and 2 sockets count for 1 server wherever hyper-threading is enabled or not. The SE2 rules I think the Standard Edition rules are quite clear now: maximum server capacity, cluster limit, minimum NUP, and processor metric. Oracle has them in the…
By Franck Pachot . I used to have many VirtualBox VMs on my laptop. But now, most of my labs are in the Cloud. Easy access from everywhere. GCP There’s the Google Cloud free VM which is not limited in time (I still have the 11g XE I’ve created 2 years ago running there) being able to use 40% of CPU with 2GB of RAM: top – 21:53:10 up 16 min, 4 users, load average:…
By Franck Pachot . In a previous post https://blog.dbi-services.com/awr-dont-store-explain-plan-predicates/ I explained this limitation in gathering filter and access predicates by Statspack and then AWR because of old bugs about reverse parsing of predicates. Oracle listens to its customers through support (enhancement requests), though the community (votes on database ideas), and through the product managers who participate in User Groups and ACE program. And here it is: in 20c the predicates are collected by AWS and…
By Franck Pachot . There are good reasons for NoSQL and semi-structured databases. And there are also many mistakes and myths. If people move from RDBMS to NoSQL because of wrong reasons, they will have a bad experience and this finally deserves NoSQL reputation. Those myths were settled by some database newbies who didn’t learn SQL and relational databases. And, rather than learning the basics of data modeling, and capabilities of SQL for data sets…
This post is the second part of https://blog.dbi-services.com/aws-aurora-xactsync-batch-commit/ where I’ve run row-by-row inserts on AWS Aurora with different size of intermediate commit. Without surprise the commit-each-row anti-pattern has a negative effect on performance. And I mentioned that this is even worse in Aurora where the session process sends directly the WAL to the network storage and waits, at commit, that it is acknowledged by at least 4 out of the 6 replicas. An Aurora specific…
By Franck Pachot . In AWS RDS you can run two flavors of the PostgreSQL managed service: the real PostgreSQL engine, compiled from the community sources, and running on EBS storage mounted by the database EC2 instance, and the Aurora which is proprietary and AWS Cloud only, where the upper layer has been taken from the community PostgreSQL. The storage layer in Aurora is completely different. In PostgreSQL, as in most RDBMS except for exclusive…
Here is my feedback after preparing and passing the AWS Database Specialty certification. There are tips about the exam but also some thoughts that came to my mind during the preparation when I had to mind-shift from a multi-purpose database system to purpose-built database services. Exam Availability This exam was in beta between last December/January and then was planned for production starting April 6, 2020. I initially planned to take the exam this first day…
By Franck Pachot . Do you remember that time where we were able to buy IBM PC clones, cheaper than the IBM PC but fully compatible? I got the same impression when testing Tibero, the TmaxSoft relational database compatible with the Oracle Database. Many Oracle customers are looking for alternatives to the Oracle Database, because of unfriendly commercial and licensing practices, like forcing the usage of expensive options or not counting vCPU for licensing. Up…
